Sperm whales are an endangered species found in Alaskan waters. Biologists have only 122 sperm whales on record in the state. A previously unrecorded whale was reported beached and dead between Haines and Juneau last week.
A private pilot spotted the body of a 48-foot male sperm whale beached on the East side of the Lynn Canal last week. It is the first time the National Oceanic Atmospheric Administration, or NOAA, has had a report of a dead sperm whale on the inside passage.
A team of marine mammal experts perform a necropsy on a male sperm whale. (Johanna Vollenweider/NOAA)
“Sperm whales—is a super rare and interesting event,” said Dr. Kathryn Savage.
She is a veterinarian, biologist, and marine mammal health specialist with NOAA fisheries in Juneau. She says sperm whales usually are found in deeper waters. That’s where their main food source, squid, are more abundant.
The sighting and a confirmation report took place last Tuesday morning. Dr. Savage led a team of eight scientists to perform a necropsy on Wednesday of last week. Scientists collected teeth to determine the whale’s age as well as blubber and tissue samples to learn more about the whale’s life and health.
“It had three deep, long parallel slices down the back just cranial to the dorsal fin,” said Dr. Savage. The whale was struck by a large vessel. She says a cruise ship, ferry, or tug is likely.
“We could see there was fractured bone and a lot of soft tissue damage. I also took some samples that would kinds confirm cause of death, but I’m pretty certain that’s what killed it.”
Their initial work was cut short when the tide came in, but they returned a couple days later to open the stomach. Knowing the stomach content is especially important because there’s a food-related tension between sperm whales and fishermen.
Sperm whales know how to get sablefish or black cod off of commercial fishing gear. Specifically, there are three sperm whales in the Gulf of Alaska that are known to snag sablefish off of long lines.
“Fortunately, we did not find any sablefish parts… It was just eating squid! We found a lot of squid beaks. And we didn’t find any plastics. I think we have pretty clean waters up here,” said Dr. Savage.
Sablefish are the reason sperm whales were first spotted in the inside passage. Fish and Game manages a sablefish fishery In the Chatham Strait. Their survey boat reported the first sperm whale sighting in 2008.
The team collected the whale’s teeth to determine age, blubber to check for contaminants, and a variety of tissue samples to enable future studies and understand factors that contributed to the whale’s death. (Johanna Vollenweider/NOAA )
“Since then, since 2008, we’ve had reports almost every year from commercial fisherman or the survey boat or both of sperm whales in Chatham Straight kind of around long line fishing vessels,” said Lauren Wild. Wild has worked with Southeast Alaska Sperm Whale Avoidance Project (SEASWAP) for a decade. It’s a group of biologists and fishermen that work together to reduce interactions between whales and fishing boats.
Wild is pursuing her PhD at the College of Fisheries and Ocean Science at the University of Alaska Fairbanks. She specializes in understanding sperm whale movement, habitat preference, and diet. She says that even after the fishery closed in Chatham Strait, some whales stuck around.
“They were moving north into Lynn Canal a little bit and exploring northern waters which was unexpected for us to see, it’s fairly surprising because it gets shallower as you go north,” she said.
She thinks the whales were following squid into the Lynn Canal. Her studies suggest that male sperm whales travel north to feed and become more attractive mates. She says the dead whale is likely a younger whale who followed older whales north.
NOAA plans to leave the whale where it lies and let nature take its course. The organization reports that someone cut off the remainder of the whale’s jaw between Wednesday and Friday of last week. Collecting marine mammal parts is prohibited under federal law.
If you see a stranded, entangled, or distressed marine mammal, call the NOAA Fisheries 24-hour stranding hotline at 1-877-925-7773.
Correction: A previous version of this story stated that Lauren Wild is a PhD candidate at the School of Fisheries and Ocean Science at the University of Alaska Fairbanks. She is a candidate at the College of Fisheries and Ocean Science at the University of Alaska Fairbanks.
